Elbow Articular Lesions and Fractures



Elbow Articular Lesions and Fractures


Edward S. Ashman



INTRODUCTION



  • Elbow articular lesions and fractures are not uncommon in the athlete. Seven percent of all fractures occur in the elbow (5). It is important for the sports physician to become familiar with patterns of injury and treatment options for athletic injuries of the elbow.


  • The elbow’s high degree of bony congruity, soft tissue aspects, and high potential for stiffness make the elbow uniquely challenging to treat after athletic injury. A common theme of elbow injuries is that early motion is important to minimize stiffness and to nourish the joint. Range of motion (ROM) required for activities of daily living is defined as 30-130 degrees of flexion and 50 degrees of supination and pronation (6). However, athletic activities may require far more motion than this.


  • Pediatric and adult elbow fractures differ considerably and will be discussed separately.


PEDIATRIC FRACTURES


Radiographic Evaluation



  • Physicians evaluating pediatric elbow fractures must be familiar with normal developmental anatomy, as well as secondary ossification centers about the elbow.


  • When obtaining radiographs, it is often helpful to obtain contralateral comparison view for comparison to differentiate between normal ossification centers and fractures.


  • The proximal radius should point to the capitellum in all views. The long axis of the ulna should line up with or be slightly medial to the long axis of the humerus on a true anteroposterior (AP) view. The anterior humeral line should bisect the capitellum on the lateral view. The humeral-capitellar (Baumann) angle should be within the range of 9-26 degrees of valgus (11).


  • A posterior fat pad sign is always considered to be an abnormal radiographic finding and represents an elbow fracture 76% of the time (9).


  • An anterior fat pad sign represents a superficial part of anterior fat pad and should be in front of the coronoid fossa. In normal elbow, the anterior fat pad should be barely visualized.


  • Look for small radiolucent area between bony rim and moderate opaque shadows of brachialis.


  • With joint effusion, there will be anterior and superior displacement of anterior fat pad (9).


Ossification Centers of the Elbow



  • Capitellum (appears at age 1-2 years)


  • Radial head (appears at age 2-4 years)


  • Medial epicondyle (appears at age 4-6 years)


  • Trochlea (appears at age 8-11 years)


  • Olecranon (appears at age 9-11 years)


  • Lateral epicondyle (appears at age 10-11 years) (11)


  • A well-known, but ribald, mnemonic exists to remember this order but will not be repeated here. (So sue me; just remember: you Can’t Resist My Team Of Lawyers.)


Supracondylar Fractures



  • Extraarticular supracondylar fractures are the most common elbow fracture in the pediatric population and represent 10% of all pediatric fractures. Most occur due to a fall on the hand or elbow. Extension pattern is far more common (98%) (11).


  • Performance of a careful neurovascular examination is crucial. Any of the neurovascular structures crossing the elbow joint may be at risk. Radiographs are mandatory. The pulseless, poorly perfused hand is a true emergency. It is important to rule out vascular injury. Vascular injuries are more commonly associated with posterolateral displacement and higher grade injuries. The medial spike may tether the brachial artery. One must perform frequent rechecks of the radial pulse to document its presence, as well as its quality. An intimal arterial injury may not be initially apparent but may develop over hours. Compartment syndromes must be treated emergently, and a high degree of clinical suspicion for this complication must be maintained, as a missed compartment syndrome may lead to catastrophic results (8).



  • The anterior interosseous (AI) nerve is the most frequently injured nerve, but most recover spontaneously within 6 months. The AI nerve can be checked by having the patient make an “OK” sign. With posteromedial displacement, the lateral spike of proximal fragment may tether the radial nerve (4).


  • Clinical signs include the “dimple sign” that occurs when the fracture ends are caught in the brachialis and subcutaneous soft tissues. The olecranon and the 2 epicondyles should form a straight line in the extended position and a triangle when the elbow is flexed to 90 degrees. This relationship is unchanged in a supracondylar fracture but is altered by an elbow dislocation (3).


  • Treatment is defined by stability of fracture pattern as defined by Gartland classification. Type I is nondisplaced, and type II exhibits anterior gapping, limited rotational malalignment, and an intact posterior hinge. Type III fractures have no cortical continuity and are totally unstable. Type I may be treated with splinting; types II and III require reduction and most require operative intervention to maintain stability while in a 90-degree position of flexion (3).


  • Following reduction, it is crucial to perform a repeat neurovascular examination and again check radiographs.


  • Potential long-term sequelae of the supracondylar fracture include the following:

May 22, 2016 | Posted by in SPORT MEDICINE | Comments Off on Elbow Articular Lesions and Fractures
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